Recently, color images are widely spread, and higher image quality has been increasingly demanded. In digital full color copiers and printers, a color image manuscript is subjected to color separation with filters of blue, green, and red, and latent images corresponding to the original image are developed with developers of yellow, magenta, and cyan, which are complementary colors of blue, green, and red, and a black developer. For this reason, the colorants in the developers of the respective colors give a great influence to image quality, particularly, color tone, transparency, and color reproducibility. In the color toners, the magenta toner is important in reproduction of a skin color. Further, the color tone of the skin in a human figure is a halftone. Accordingly, high developing properties are also demanded. For such demands, as a colorant for a magenta toner, quinacridone colorants, thioindigo colorants, xanthene colorants, monoazo colorants, perylene colorants, and diketopyrrole colorants are known.
Usually, in the case where a pigment is used in the colorant for magenta, the pigment has good light resistance property, but does not demonstrate sufficient color tone and transparency. In order to improve these properties, it is desired that the pigment is finely dispersed in a variety of media. Unfortunately, it is difficult to form a sufficiently fine pigment in a toner produced by a toner production process, and uniformly disperse the pigment.
Meanwhile, in the case where a dye is used in the colorant for magenta, the dye demonstrates a vivid magenta color in the initial period. The dye, however, has low light resistance property, and color nuance tends to greatly change after the dye is left under an ambient light. Moreover, in the case of a light color, a bright and sharp image is obtained. In a region of a dark color, however, a sufficient image density is difficult to obtain. Particularly, in the case where the colors are mixed and a dark red color and a dark blue color are reproduced, the range of the color to be reproduced is likely to be narrower. The xanthene colorant is a colorant having good color reproducibility and color tone, but the light resistance properties is significantly reduced when the colorant is used in a liquid form. Accordingly, various measures are needed (see Patent Literatures 1 and 2). Additionally, along with higher functions of the color multifunction machine these days, in order to obtain an image that satisfies the transparency and is closer to the manuscript, a magenta toner having further improved color tone, saturation, and electrophotographic properties is strongly desired.